Binding interactions between bovine neurophysins and small analogs of the hormones oxytocin and vasopressin will be quantitated as a function of temperature in order to determine the different thermodynamic parameters associated with the binding of each segment of the peptide. NMR studies of the interaction should enable determination of distances between bound peptide and selected residues on neurophysin. Sequence studies of bovine-neurophysin-l will be completed. Co(III)- protein interactions will be studied further with particular emphasis on the properties and stability of Co (III)-carbonic anhydrase. Studies of Zn (II)-apoferritin interaction will be initiated in order to determine the mechanism by which Zn (II) inhibits incorporation of iron into ferritin.